Extractor for a bone connection element

ABSTRACT

An extractor device is provided to extract an insert to be used with a bone connection element such as a bone plate having at least one opening for a bone screw used with said insert. The extractor device has an outer hollow sleeve having proximal abutment surface being able to engage a surface portion of the bone connection element, and an inner bar having a diameter enabling the insertion of the bar into the hollow sleeve. The bar has a threaded leading end to engage the thread of the insert to be extracted. The hollow sleeve has an inner thread and the inner bar has an outer threaded element for engaging the inner thread of the hollow sleeve. The outer threaded element is positioned with respect to the bar in a longitudinal position to enable the thread at its leading end to extend beyond the proximal abutment surface of the sleeve to be threaded into the insert.

BACKGROUND

The invention concerns an extractor device for an insert to be used witha bone connection element usable within an implantable orthopedic devicehaving a load-bearing element such as a bone plate with at least oneopening for a fixation element such as a bone screw. A screw can be usedsuch as shown in the application entitled “Self-Guiding ThreadedFastener” with inventor Yves Crozet filed on Nov. 30, 2004 the entiredisclosure of which is incorporated herein by reference. The inventionis furthermore related to the insert itself and to an insertion devicefor such an insert. The inserts may be used in bone plating systems suchas described in the application entitled “Bone Plating Implants,Instruments and Methods” filed Nov. 30, 2004 listing Yves Crozet,Christian Lutz and Renee Wirth as inventors the disclosure of which ishereby incorporated by reference.

Such an insert is provided that can be inserted into the opening in areceptacle in which the external shape of the insert is at leastpartially complementary to the internal shape of the receptacle. Theinsert has a central through-bore for mounting a body of the fixationelement. The implantable orthopedic device has a structure for holdingthe insert in the receptacle.

A series of implantable orthopedic devices with load-bearing elements,such as bone plates, with openings for the insertion of fixationelements in such load-bearers are known from the prior art. Among themare proposals for the mono-axial as well as poly-axial attachment offixation elements, particularly screws.

As an example for a device of this type having poly-axial attachment ofscrews in load-bearing elements is shown in U.S. Pat. No. 5,954,722.Other bone plates with inserts are shown in U.S. Pat. Nos. 5,269,784,5,976,141 and 5,607,428. One advantageous insert is shown in WO2004/082493, which is hereby incorporated by reference.

FIG. 1 OF WO 2004/082493 shows a perspective view of an insert to beused with a load-bearing element such as a bone plate. FIG. 2 is asectional side view of a load-bearing element with another insertinserted. The load-bearing elements can be equipped in advance withstandard inserts. This enables an easier more cost efficient productionof bone plates giving the surgeon the possibility to adapt the boneplate according to his needs. A surgeon thus may turn an opening in abone plate adapted to receive a non-locking screw to an aperture inwhich a locking screw having a threaded portion adapted to threadablyengage the plate via the insert can be used. Then it may sometimes benecessary to extract one or the other insert and to replace it byanother different insert or to leave the bore or opening empty. Theprior art exhibits the disadvantage that there are no extracting toolsprovided to help the surgeon team to extract inserts.

SUMMARY OF THE INVENTION

It is therefore one aspect of the invention to provide an extractordevice allowing to extract easily different inserts from differentload-bearing elements.

This aspect is fulfilled according to the invention for an extractordevice of the aforementioned type which can easily remove an insert froma bone plate opening so that it may receive a non-locking screw.

This object is achieved by an extractor device, which can engage theinsert in a manner that enables the extraction of the said insert fromthe load-bearing element in a simple and swift movement. The extractioncan be accomplished for quite a number of different inserts, withdifferent angled positions. Of particular advantage is that the secureextraction of the insert can be assured directly and automatically withthe use of the extractor device.

One single extractor device is sufficient to provide the necessary helpto extract various inserts with inclined axes as long as the inner borehas a predefined thread. The surgeon can therefore use a bone plate withinserts with predefined angles for the insertion of poly- or monoaxialscrews and change one or more of the inserts to orient bone screws at anumber of different defined angles in a simple manner.

It is another aspect of the invention to provide an insert, which iseasy to handle for the surgeon.

It is furthermore an aspect of the invention to provide an insertiondevice allowing a simple insertion of different inserts into differentload-bearing elements.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood on reading the followingdetailed description of non-limiting embodiments thereof, and onexamining the accompanying drawings, in which:

FIG. 1 is a top view of a load-bearing element in the form of a boneplate with a row of attachment bores;

FIG. 2 is a perspective view of a first insert to be used with aload-bearing element;

FIG. 3 is a sectional side view of a load-bearing element with a secondinsert inserted;

FIG. 4 is a perspective view of an extractor device according to oneembodiment of the invention;

FIG. 5 is a side view of the device according to FIG. 4;

FIG. 6 is a sectional side view of the external sleeve of the extractordevice according to FIG. 4;

FIG. 7 is a perspective view of the inner bar of the extractor deviceaccording to FIG. 4;

FIG. 8 is a sectional side view of the inner bar of FIG. 7;

FIG. 9 is an enlarged view of the tip of the inner bar of FIG. 7;

FIG. 10 is a sectional side view of an extractor device according to asecond embodiment of the invention in vicinity of an load-bearingelement;

FIG. 11 is a side view of an insertion device according to an embodimentof the invention;

FIG. 12 is an detail of the tip of the insertion device according toFIG. 11;

FIG. 13 is a perspective view of a second insert to be used with aload-bearing element;

FIG. 14 is a sectional side view of the insert according to FIG. 13; and

FIG. 15 is an enlarged side view showing a detail of the insertaccording to FIG. 13.

DETAILED DESCRIPTION

Referring to FIG. 1 there is shown a top view of a load-bearing elementin the form of a plate 1 with a row of attachment bores 2 arranged alongthe longitudinal direction of plate 1. FIG. 2 shows a perspective viewof a first insert 10 to be used with a load-bearing element 1. Bores 2of plate 1 are through-bores that exhibit an oval central opening 3. Atopening 3 there are two sidewalls 5 on opposite sides of axis 4, whichextend parallel to the direction of longitudinal axis 4 of plate 1 andextend at right angles to the surfaces of the plate. These parallelsidewalls 5 are connected on both ends by semicircular walls 6, eachforming a semi-cylindrical boundary so that together the aforementionedoval opening 3 results.

In other forms of the plate, oval bores 2 can also be provided. Bores 2can also be elliptical or of a common elongated form. What is essentialis the multiplicity of functions for the selection of attachmentelements or fasteners made possible by insert 10 shown in FIG. 2.Through the mostly elongated form of plate 1, elongated bores 2 arepreferred over circular bores in order to maintain flexibility with theinsertion of screws with larger diameters. The bore may also beessentially cylindrical with the disadvantage that the insert 10 hasless material for providing inclined holes in the insert 10.

Arranged around the cylindrical, not necessarily circular walls 5, 6forming opening 3 is chamfered surface area 7, extending and taperinginwardly from the upper surface 8 of plate 1 that faces away from thebone during implantation. The form of this area 7 is preferablypart-spherical.

The top surface 8 of load-bearing element 1 is formed somewhat deeper inthe side area 18 near bores 2. The same is true for upper edge 15 ofsidewall 5, which are shown to be lower (closer to the plate bottomsurface) in a direction opposite the bore ends in longitudinal direction4. Bottom surface 9, which is closest to the bone in insertion duringsurgery is here locally flat. Normally, plates 1 can exhibit continuoussurfaces 8 and undersurfaces 9 which at each point, for the function ofpositioning on the bone can always be considered to be flat. But heretoo, positioning on curved or bent surfaces can be provided.

FIG. 2 shows a perspective view of an insert 10 to be used with aload-bearing element 1 according to FIG. 1. Similar characteristicsappear in all figures with the same reference numerals. Each insert 10is designed to be shaped complementary to bore 2 for locking thereinwith respect to areas 7 and sidewalls 5. Insert 10 has a central bore 11with an internal threading 12. Internal threading 12 can be cylindricalor slightly conical. Insert 10 can have an area that extends beyondlower surface 9 of plate 1 that is adjacent the bone. In particular,insert 10 has locking mechanisms along its edges. In particular, thelocking mechanism can be two projecting rims that engage the underside 9of plate 1 after the insertion of insert 10. The insert 10, when it isinserted into plate 1, with its extension area, can form a distancespacer with regard to the bone material into which a screw that has beeninserted into bore 11 is turned.

It is also possible that, at least along the length of the longitudinalaxis 4 of the load-bearing element 1, a recess 33 is provided on thebottom surface 9 around opening 2 of the plate 1. This recess can alsobe provided on the narrow side. In addition, insert 10 is provided witha projecting rim 27 that is arranged in such a way that the bottom ofinsert 10 does not project beyond lower surface 9. The underside ofinsert 10 is thus at least flush with the aforementioned surface 9 ofthe load-bearing element 1.

The reference numeral 21 refers to the surface of insert 10 having acircumference 22 that meets with the edge of area 8 of plate 1. Aspherical surface 23 extends downwardly from surface 21 and is shaped soas to have complementary surface contact with surface 7. Semicircularextension 24 extends downwardly from surface 23 and is in conformingcontact, without any significant play, with area 6 of bore 2.

The area lying opposite the longitudinal surface 5 consists of aresilient extension 25 on each side, in which, in the preferredembodiment shown, each extension 25 is provided with slots 26. Eachextension 25 has, on its lower edge, a projecting rim 27 facing outwardfrom the point of view of the insert with an upward-facing shoulder 28with an outer edge 29. The surface of rim 27 that is facing toward thebone can be inclined. Extension 25 is also to a certain extent,flexible. In inserting insert 10, extension 25 then slides into bore 2and is deflected inwardly by the projecting rim 27. Once insert 10 iscompletely inserted, shoulder 28 slides against underside 9 of plate 1and locks insert 10 in plate 1. This locking is additionally ensured bythe subsequent insertion of a bone screw (not shown). FIGS. 13 thru 15show a slightly modified insert having tapered side elements orsidewalls 25 a which taper inwardly from their free edges 127 to surface23 a. The insert will be described in more detail below.

It is one aspect of the invention to provide an extractor device beingable to extract such a fixed insert 10 from the plate 1. Pressure has tobe exerted in such a way that an inward deflection of extension 25, 25 ais obtained so that projecting rim 27, 127 is no longer secured underplate 1 or in a recess provided at the bottom of the plate 1. It shouldbe noted that the extractor device has to also function if extension 25,and with it projecting rim 27, are not arranged as two extensions 25 onthe opposing longer sides of insert 10. The design can also includeresilient extensions on the narrow sides of an insert, i.e.corresponding to the location of the semicircular cylindrical extensions24. Extensions 25 can also be arranged in an alternating manner. Therecan also be only one or two more extensions.

Referring to FIG. 4 there is shown a perspective view of an extractordevice 50 according to a preferred embodiment of the invention.Extractor device 50 comprises two different parts, an outer sleeve 60and an inner bar 70 extending on both sides beyond the through goingbore or cannulation inside the sleeve 60. The outer sleeve 60 is shownin greater detail in FIG. 6, the inner bar 70 is shown in greater detailin FIG. 7 to 9.

FIG. 5 shows a side view of the device 50 according to FIG. 4. The outersleeve 60 comprises a hollow sleeve part 61 having a first handle part62 being an integral part of the sleeve 60. The first handle part 62comprises a circumferential depression 65 to provide a grip portion forthe hand of a user of the device 50. A thickened abutment sleeve 63 isprovided on the opposite end of the hollow sleeve part 61 ending in around abutment ring 64 having a larger diameter than the diameter of theproximal bar section 73 of the inner bar 70. The function of theabutment ring 64 will be explained below. The length of the externalsleeve 60 can be between 150 and 200 millimeter with a first handle part62 diameter of 30 to 50 millimeter and a outer sleeve diameter of e.g.14 millimeter.

It can be seen from both, FIGS. 4 and 5 that the preferred inner bar 70extends beyond both ends of outer sleeve 60. On the side of the firsthandle part 62 the inner bar 70 comprises a second handle part 72 havinga circumferential gripping depression 75. The radius of the secondhandle part 72 is greater than the inner diameter of the hollow sleeve60. An engagement thread 71 is provided at the end of the proximal barsection 73 extending beyond the hollow sleeve 60.

FIG. 6 shows a sectional side view of the preferred external sleeve 60of extractor device 50 according to FIG. 4. The hollow sleeve comprisesa through-bore extending along axis 82 a with a middle section 66 havinga first diameter and extending from the opening 67 at the distal endnear the first handle part 62 towards an internal thread 68. Thethrough-bore comprises on its proximal end 69 a second diameter beingsmaller than the above-mentioned first inner diameter. The internalthread 68 can have a length of e.g. 10 millimeter with 5 to 10 fullthreads. The internal thread 68 is positioned near the proximal end ofthe sleeve 60, e.g. between 20 and 40 millimeter from the abutment ring64. It would also be possible to locate the internal thread 68 near orunder the first handle part 62.

The first inner diameter, being the inner diameter of a part of thesleeve 60, can be chosen to be 12 Millimeter, said second diameter ofthe end portion 69 can be chosen to be 11 millimeter. The enlargedsection 63 can have a diameter of 14 millimeter.

FIG. 7 shows a perspective view of the preferred inner bar 70 of theextractor device 50 according to FIG. 4. FIG. 8 shows a sectional sideview of the inner bar 70 of FIG. 7. The inner bar 70 comprises a firstdistal bar portion 74 having an outer diameter similar to the firstinner diameter of the hollow sleeve 60 so that the bar 70 can beinserted with little play into the hollow sleeve 60 from the side of theopening 67. The distal bar portion 74 ends in an abutment flange 76 ofthe gripping depression 75. On the opposite end of the distal barportion 74 a middle bar portion 77 has a thinner cylindrical portion.The middle bar portion 77 is followed, by a threaded portion 78 having alongitudinal length which is preferably identical to the inner threadedportion 68 of the outer sleeve 60. The location of thread 78 alsodepends on the location of the inner threaded portion 68. If portion 68is located near or under the first handle part 62 then the threadedportion 78 of the inner bar 70 is located near or in the area of thedistal bar portion 74.

In the embodiment shown in the drawings, the threaded portion 78 isproximally followed by the proximal inner bar section 73. Inner barsection 73 is followed by a tip portion 71 of the inner bar 70, which isshown in FIG. 9 in an enlarged view.

The tip portion 71 preferably comprises four full threads of a thread 80ending in a flat surface 81. In the preferred embodiment the thread 80is conical and is connected with the inner bar section 73 via achamfered flange 79. The direction of the threading 80 is identical tothe direction of the thread 78. The main axis 82 of the bar 70 coincideswith the axis 82 of the thread 80 and with the longitudinal main axis 82a of the sleeve 60. The advantage of a conical thread 80 is the easierfixation of the bar onto inserts 10 with damaged threads 12.

The function of the device 50 is as follows. The device is assembledthrough insertion of the bar 70 into the hollow sleeve 60 through thedistal opening 67 within the sleeve 60 such that axis 82, 82 a andcoaxial. The thread 78 of the bar 70 engages the inner thread 68 of thehollow sleeve 60 and is rotated until the tip 71 is extending beyond theend of the hollow shaft 60 or until the threads 68 and 78 come free onefrom the other. Both threads 68 and 79 are right-handed, i.e. the thread78 advances when turned clockwise with respect to its mating part 68.The flange 76 of the second handle part 72 can ultimately abut againstthe first handle part 62 of the hollow sleeve 60. The thread 78 may thenno longer be in engagement with thread 68.

The bar 70 is then screwed into the insert 10 by turning the handle 72,i.e. the conical thread 80 is engaging the internal threading 12 of theinsert 10. Preferably the abutment flange 79 of the tip is coming intocontact with the upper surface 21 of the insert 10. Then the abutmentring 64 is advanced to come into contact with the surface 8 of the plate1 beside the insert 10, i.e. the abutment ring 64 does not contactsurface 21 but touches the plate 1 outside the circumference 21 of theinsert 10. This contact is possible independent from the angle anddirection of the insert bore 11 as discussed above. The relativeadvancement of sleeve 60 in relation to the bar 70 can be a longitudinalmovement or comprising a rotation when the threads 68 and 78 come intoengagement. For a rotational movement the handle part 62 is rotatedagainst the handle part 72 of the inner bar, which is maintained in itsposition. The internal thread 12 of the insert 10 is also right-handed.

When the abutment ring 64 comes in contact with the upper surface 8 ofthe plate 1 (and not with the insert 10), then the extractor sleeve 60is further rotated in the direction opposite to the above mentionedrotation of the bar 70. This rotation retracts the rod 73 further intothe sleeve 60 and therefore exerts a force in the longitudinal directionof axis 82 of the extractor device 50 on the insert 10 against the plate1. This leads to the situation that engagement means 25 of the insert 10are overcome and the insert 10 will be extracted. The advantage ofright-handed threads 68 and 78 resides in the fact that the rotation toextract the insert 10 additionally blocks the thread 12 of the insert 10in thread 80 of the tip 71.

In another embodiment (not shown) the threads 68 and 78 may beleft-handed. Then the surgeon has the usual anti-clockwise movement toextract the insert; however, it is then possible that the thread 12 ofthe insert 10 becomes no longer fastened to the conical thread 80 of theinner bar 70.

It is clear that the abutment ring 64 can be of a different form thanhaving a circular shape. It may have a polygonal abutment surface or theplane of the abutment surface can comprise an angle with the planeperpendicular to the longitudinal direction of axis 82 of the bar 70.

FIG. 10 shows a sectional side view of an extractor device 90 accordingto a second embodiment of the invention in vicinity of an load-bearingelement 1. Extractor device 90 comprises three different parts, an outersleeve 60 and an inner bar 70 extending on both sides beyond the throughgoing bore inside the sleeve 60. Additionally there is an intermediateelement 91 essential to the function of the device.

The outer sleeve 60 comprises a hollow sleeve part 61 having a firsthandle part 62 being an integral part of the sleeve 60. The first handlepart 62 comprises a circumferential depression 65 to provide a gripportion for the hand of a user of the device 50. A thickened abutmentsleeve 63 is provided on the opposite end of the hollow sleeve part 61ending in a round abutment ring 64 having a larger diameter than thediameter of the proximal bar section 73 of the inner bar 70. Thefunction of the abutment ring 64 is identical as explained above.

The inner bar 70 extends on both sides of outer sleeve 60. On the sideof the first handle part 62 the inner bar 70 comprises a second handlepart 72 having a circumferential gripping depression 75. Between the twohandle parts 62 and 72 the intermediate element 91 is introduced.

The intermediate element 91 has a through bore 93 for the inner bar 70.The intermediate element 91 comprises a grip portion 92 being able to bein abutment against the handle part 72 of inner bar 70 on one side andwith the handle part 62 of the sleeve 60 on the other side. On the sideof the handle part 72 the intermediate element 91 comprises an opening97 in the flat upper surface to receive the inner bar 70. On the side ofthe handle part 62 the intermediate element 91 comprises a smallercentral projection 94 with an external thread 98.

Sleeve 60 incorporates in the handle part 62 a recess 95 to accommodatethe projection 94, wherein the recess 95 comprises an internal thread108.

As in the first embodiment of an extractor device 50, an engagementthread 71 is provided at the leading end of the proximal bar section 73extending beyond the hollow sleeve 60.

Inner bar 70 of the extractor device 90 comprises a bar portion 74having an outer diameter similar to the inner diameter of the hollowsleeve 60 and similar to the inner diameter of the intermediate element91 so that the bar 70 can be inserted with little play into theintermediate element 91 and into the hollow sleeve 60 from the side ofthe openings 67 and 97. The bar portion 74 ends in an abutment flange 76of the gripping depression 75.

The tip portion 71 of extractor device 90 can be the same as the tipportion 71 of extractor device 50.

The function of the device 90 is as follows. The device is assembledthrough insertion of the intermediate element 91 into the hollow sleeve60 through the opening 67 within the sleeve 60. The thread 98 of theintermediate element 91 engages the inner thread 108 of the hollowsleeve 60 and is rotated until the handle part 92 abuts against thehandle part 62 or the projection 94 reaches the depth of the recess 95.Both threads 98 and 108 are right-handed. The bar 70 is then enteredinto intermediate element 91 and hollow sleeve 60 and screwed into theinsert 10 by turning the handle 72, i.e. the conical thread 80 isengaging the internal threading 12 of the insert 10. Then the abutmentring 64 is advanced to come into contact with the surface 8 of the plate1 beside the insert 10, i.e. the abutment ring 64 does not contactsurface 21 but touches the plate 1 outside the circumference 21 of theinsert 10.

The handle part 92 of the intermediate element 91 is rotated against thehandle part 62 of the hollow sleeve 60, which is maintained in itsposition. As rotation occurs, the intermediate element 91 and the hollowsleeve 60 move apart, while the inner bar 70 just follows, because thehandle part 72 is in abutment with the intermediate element 91. Therotation of intermediate element 91 indirectly retracts the rod 73further into the sleeve 60 and therefore exerts a force in thelongitudinal direction of said axis 82 of the extractor device 90 on theinsert 10 against the plate 1. This leads to the situation thatengagement means 25 of the insert 10 are overcome and the insert 10 willbe extracted. In the case of the second embodiment it is advantageous touse right-handed threads 80 and 12 whereas threads 98 and 108 areleft-handed. Then the rotation to extract the insert 10 blocks theinsert 10 in thread 80 of tip 71.

However in all embodiments it is possible to switch the handedness ofany pair of threads.

Upon extraction of an insert 10, the insert 10 either completely ornearly disappears within the hollow thickened abutment sleeve 63.

FIG. 11 shows a side view of an insertion device 100 according to anembodiment of the invention and FIG. 12 is an detail of the tip of theinsertion device 100 according to FIG. 11. Insertion device 100 is verysimilar to inner bar 70, having a bar 101 with a handle part 102 at oneend, whereas the other free end of the bar 101 comprises a cylindricaltip 103 with a smaller diameter than the bar 102. Said tip 103 comprisesone single thread 105 and ends with a flat bottom surface 104, which canbe chamfered for easier insertion. Tip 103 is positioned within theopening of an insert 10 and the thread 105 engages the complementarythread 12 of the insert 10. It is clear that due to the shortness of thetip 103 the resilient extensions 25 of insert 10 are not in the vicinityof the tip 103 but spaced apart in the longitudinal direction of axis 82b of the insertion tool 100. It is possible that the distance betweenthe thread 12 and the upper surface 21 of the insert 10 is such thatsaid surface 21 can abut against the abutment flange 109 of the bar 101.

Initially the insert 10, 20 to be inserted into a plate 1 is affixed tothe insertion device 100 as mentioned above. Then the device 100 withthe insert 10, 20 at its tip is pushed against and into the plate 1until the locking extensions 25 of the insert 10, 20 are pushed beyondthe smallest waist part, i.e. the smallest diameter in the hole 2 of aplate 1. Then the insertion device 100 can be rotated in the oppositedirection to free the insert 10, 20 from its tip. This can be donedirectly, because the inserts 10, 20 are oblong.

FIG. 13 shows a perspective view of a second insert 110 to be used witha load-bearing element 1. FIG. 14 is a sectional side view of the insert110 according to FIG. 13 and FIG. 15 is an enlarged side view showing adetail of the resilient extension 25 a of the insert according to FIG.13. Insert 110 comprises a flat upper surface 121 at its circumferencewherein on the inside of surface 121 a step-like recess 122 is provided.The resilient extension 25 a on each side is separated as within theembodiment according to FIG. 1 from the semicircular extensions 24 a bytwo slots 26 a. The resilient extension 25 a comprises a specialtriangular form when seen from the side or in a cross section.

On the inside the resilient extension 25 a comprises the inner thread 12which can be oriented in different ways and angles. On the outside theinsert 110 has a waist 129, i.e. an area with minimum exterior diameter.Towards the upper side 121 of the insert 110 there is the largerspherical surface 23 a or another complementary surface for the bore 2in plate 1. Towards the bottom side there is provided, on the resilientextensions 25 a, a thickened region 127. In the embodiment shown thethickened region 127 has a thickest part near the lower end of theextension 25 a, i.e. the cross section through the extension 25 a alwaysshows a triangle form. Advantageously the form of the plate 1 iscomplementary, i.e. the plate has at least on its sides a recess toaccommodate the thickened region 127. The chamfered lower end 128facilitates the introduction of the insert 110 into a plate 1. The angleof the surface 128 in relation to the bottom surface is 120 degree(reference numeral 124). The triangle form 127 also facilitates theextraction of the insert 110 because the inclined surface 126, e.g. withan angle of 30 degree to the vertical axis of the insert 110, can slideon the complementary inclined surface of the plate 1 or on the smallestinternal diameter of hole 2 thereof.

Although the described drawings already show a whole series of possibleconfigurations of the invention, the invention is and should be limitedonly by the parameters of the attached claims.

The advantage of the invention is that it offers the surgeon using aplate 1 with conventional standard bores 2 and inserted inserts 10, 110the possibility of adapting the plurality of angularly-stable mono-axialbores by replacement of inserts, and furthermore, that this is madepossible intra-operatively.

1. An extractor device for an insert to be used with a bone connectionelement usable within an implantable orthopedic device having aload-bearing element with at least one opening for receiving a fixationelement such as a bone screw with the insert thereon, the extractordevice comprising: an outer hollow sleeve, the hollow sleeve comprisinga introduction opening at a first end and a proximal abutment surface ata second end engagable with a surface portion of the load-bearingelement around the insert, the hollow sleeve further comprising an innerthreaded portion between said introduction opening and said abutmentsurface, an inner bar, the bar having a diameter enabling the insertionof the bar into said distal introduction opening of the hollow sleeveand comprising a threaded portion engaging the thread of the insert tobe extracted, wherein, alternatively, the inner bar further comprises anouter thread or an intermediate element is provided with a central boreto accommodate said inner bar and comprising an outer thread, whereinthe outer threaded portion is arranged to engage said inner threadedportion of the hollow sleeve, said outer threaded portion of said innerbar being positioned on the bar or the intermediate element at alongitudinal distance from the insert engaging threaded portion toenable that threaded portion to extend beyond the proximal abutmentsurface to be threaded in the insert.
 2. The extractor device as setforth in claim 1, wherein the insert engaging threaded portion of thebar has a conical thread.
 3. The extractor device as set forth in claim1, wherein an abutment flange connects insert engaging threaded portionwith a larger bar section of said inner bar.
 4. The extractor device asset forth in claim 1, wherein the inner bar comprises at a first end ahandle part having an abutment flange.
 5. The extractor device as setforth in claim 1, wherein the hollow sleeve comprises at its second endan enlarged abutment section to engage a surface of the load-bearingelement.
 6. The extractor device as set forth in claim 5, wherein thehollow sleeve comprises at its first end a hollow handle part.
 7. Theextractor device as set forth in claim 1, wherein the threads of sleeveand bar, respectively, are located in the first third of the device onmoving from said first end of said outer sleeve to said second end. 8.The extractor device as set forth in claim 1, wherein the threads ofsleeve and bar or intermediate element have the same handedness than thethread of the tip of the inner bar.
 9. The extractor device as set forthin claim 1, wherein the abutment surface is a cylindrical ring, anelliptical ring or a polygonal strip.
 10. A method for extracting aninternally threaded insert from an opening in a bone connection elementusable within an implantable orthopedic device, such as a bone plate:inserting a bar with a threaded tip and an outer threading into a hollowsleeve having an internal threading for engaging the outer threading ofthe bar and an abutment tip for engaging the bone plate; screwing thetip of the bar into the internal threading of the insert to beextracted, preferably until an abutment flange of the tip comes intocontact with an upper surface of the insert, advancing the abutment tipof the hollow sleeve into contact with a surface of the bone connectionelement, wherein the relative advancement of the hollow sleeve relativeto the bar is a longitudinal movement resulting from rotating theengaged inner and outer threads of sleeve and bar; extracting the insertthrough further rotation of sleeve or an intermediate element locatedbetween the sleeve and the bar, wherein the inner bar or the sleeve,respectively, are maintained in its rotational position, said rotationretracting the bar into the hollow sleeve and exerting a force in alongitudinal direction of the sleeve and bar on the insert againstforces holding the insert within the opening in the bone connectionelement and extracting the insert.
 11. The method as set forth in claim10, wherein the extractor device is assembled by inserting the inner barinto the hollow sleeve from an opening at a first end of the hollowsleeve and relative rotation of the hollow sleeve and bar to engagetheir inner and outer threads, respectively, until the tip of the bar isextends beyond a second end of the hollow sleeve.
 12. An extraction toolfor an internally threaded insert located within an opening in a boneplate comprising: a tubular sleeve having an internal bore with athreaded portion intermediate first and second ends thereof; a bar forinsertion within the internal bore of said tubular sleeve, said barhaving a threaded first end and a threaded element located intermediatesaid first end and a second end of said bar, said threaded elementthreadably engagable with said threaded outer sleeve portion, saidthreaded sleeve portion and said threaded element respectively locatedbetween the first and second ends of said sleeve and bar such that saidthreaded first end of said bar extends beyond said first sleeve end whenat least a portion of said threaded portions are engaged.
 13. Theextraction tool of claim 12 wherein the first end of said tubular sleeveincludes an abutment portion.
 14. The extraction tool of claim 13wherein said second end of said tubular sleeve has a drive portion forrotating said sleeve.
 15. The extraction tool of claim 14 wherein saidsecond end of said bar has a drive portion for rotating said bar.
 16. Aninsertion device for use with an insert to be used with a boneconnection element usable within an implantable orthopedic device, theinsert having at least one threaded opening for a fixation element, theinsert having inwardly deformable sidewalls for engaging walls of saidopening, the insertion device comprising: a bar having a threadedportion at one end thereof to engage the thread in the opening of theinsert to be inserted, wherein a length of the threaded end portion ofsaid inner bar is shorter than a thickness of the insert to avoidengagement of the threaded bar portion with the deformable sidewalls ofsaid insert.
 17. An insert for use with an orthopaedic device such as abone plate with at least one opening for receiving a fixation elementengagable with said insert, the insert comprising an external surfacethat is at least partially complementary to an internal shape of theopening, wherein the insert has a central threaded through-bore formounting a body of the fixation element, and in which the insert hasresilient sidewalls for holding the insert in the opening whichsidewalls have a thickened part which can be positioned adjacent aninternal portion of said opening.
 18. The insert as set forth in claim17 wherein said thickened part tapers inwardly towards saidthrough-bore.